/*
 * Copyright (c) 1993-2022, NVIDIA CORPORATION. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef ENTROPY_CALIBRATOR_H
#define ENTROPY_CALIBRATOR_H

#include "BatchStream.h"
#include "NvInfer.h"

//! \class EntropyCalibratorImpl
//!
//! \brief Implements common functionality for Entropy calibrators.
//!
template <typename TBatchStream>
class EntropyCalibratorImpl {
 public:
  EntropyCalibratorImpl(TBatchStream stream, int firstBatch,
                        std::string networkName, const char* inputBlobName,
                        bool readCache = true)
      : mStream{stream},
        mCalibrationTableName("CalibrationTable" + networkName),
        mInputBlobName(inputBlobName),
        mReadCache(readCache) {
    nvinfer1::Dims dims = mStream.getDims();
    mInputCount = samplesCommon::volume(dims);
    CHECK(cudaMalloc(&mDeviceInput, mInputCount * sizeof(float)));
    mStream.reset(firstBatch);
  }

  virtual ~EntropyCalibratorImpl() { CHECK(cudaFree(mDeviceInput)); }

  int getBatchSize() const noexcept { return mStream.getBatchSize(); }

  bool getBatch(void* bindings[], const char* names[],
                int nbBindings) noexcept {
    if (!mStream.next()) {
      return false;
    }
    CHECK(cudaMemcpy(mDeviceInput, mStream.getBatch(),
                     mInputCount * sizeof(float), cudaMemcpyHostToDevice));
    ASSERT(!strcmp(names[0], mInputBlobName));
    bindings[0] = mDeviceInput;
    return true;
  }

  const void* readCalibrationCache(size_t& length) noexcept {
    mCalibrationCache.clear();
    std::ifstream input(mCalibrationTableName, std::ios::binary);
    input >> std::noskipws;
    if (mReadCache && input.good()) {
      std::copy(std::istream_iterator<char>(input),
                std::istream_iterator<char>(),
                std::back_inserter(mCalibrationCache));
    }
    length = mCalibrationCache.size();
    return length ? mCalibrationCache.data() : nullptr;
  }

  void writeCalibrationCache(const void* cache, size_t length) noexcept {
    std::ofstream output(mCalibrationTableName, std::ios::binary);
    output.write(reinterpret_cast<const char*>(cache), length);
  }

 private:
  TBatchStream mStream;
  size_t mInputCount;
  std::string mCalibrationTableName;
  const char* mInputBlobName;
  bool mReadCache{true};
  void* mDeviceInput{nullptr};
  std::vector<char> mCalibrationCache;
};

//! \class Int8EntropyCalibrator2
//!
//! \brief Implements Entropy calibrator 2.
//!  CalibrationAlgoType is kENTROPY_CALIBRATION_2.
//!
template <typename TBatchStream>
class Int8EntropyCalibrator2 : public IInt8EntropyCalibrator2 {
 public:
  Int8EntropyCalibrator2(TBatchStream stream, int firstBatch,
                         const char* networkName, const char* inputBlobName,
                         bool readCache = true)
      : mImpl(stream, firstBatch, networkName, inputBlobName, readCache) {}

  int getBatchSize() const noexcept override { return mImpl.getBatchSize(); }

  bool getBatch(void* bindings[], const char* names[],
                int nbBindings) noexcept override {
    return mImpl.getBatch(bindings, names, nbBindings);
  }

  const void* readCalibrationCache(size_t& length) noexcept override {
    return mImpl.readCalibrationCache(length);
  }

  void writeCalibrationCache(const void* cache,
                             size_t length) noexcept override {
    mImpl.writeCalibrationCache(cache, length);
  }

 private:
  EntropyCalibratorImpl<TBatchStream> mImpl;
};

#endif  // ENTROPY_CALIBRATOR_H
